Image processing apparatus and method

An image processing method comprising:

• a predicting step, of predicting whether or not there is a possibility of overflow such as would preclude a capability of storing image information for one page;
• a rendering step, of rendering image data based on image information that has been stored, when a result of said predicting step predicts that there is a possibility of overflow;
• a compressing step, of compressing the image data rendered in said rendering step;
• a storing step, of storing the image data compressed in said compressing step;
• an expanding step, of expanding compressed image data stored in said storing step;
• a reception controlling step, of deleting image information that has been used for rendering, and of receiving subsequent image information;
• a monitoring step, of monitoring an amount of compressed image data compressed in said compressing step;
• a resolution converting step, of converting the resolution of image data rendered in said rendering step on a basis of the amount of compressed image data monitored in said monitoring step so as to reduce the amount of image data after the compressing in said compressing step;
• and
• an output step, of outputting processed image data, processed by said image processing method, to a printer,
• wherein said output step comprises a step of converting a resolution of image data expanded in said expanding step to a predetermined resolution for printing by a smoothing process to prepare the processed image data to be output to the printer when the expanded image data expanded in said expanding step has a low resolution due to the conversion in said resolution converting step.

An image processing apparatus, comprising:

• a computer which generates image data on a page basis;
• a converter which converts a given page of image data generated by said computer into a plurality of bands and generates a display list;
• an intermediate memory which stores the display list of the plurality of bands comprising the given page from said converter;
• a rendering unit which refers to the display list stored in said intermediate memory and generates rendering commands for rendering one band at a time;
• a band buffer having an input and an output, including at least two buffers, each such buffer being adapted to store one band, wherein, when one band is read into the first input from said rendering unit and is stored in one buffer being, another band is read out from another buffer to the output, and vise versa;
• an image processor having first and second inputs and an output, and which receives bands in real time at the first input from said band buffer;
• a compressor for compressing bands output from said band buffer;
• a compressed image memory for storing the compressed bands from said compressor;
• an expander for expanding the compressed bands stored in said compressed image memory, and outputting the expanded bands to the second input of said image processor;
• a capacity detector for said intermediate memory, for determining if there is a possibility of overflow based on more than a predetermined number of bands being stored in said intermediate memory prior to receiving an end of print data command from said computer for the given page, and if a determination is made that there is a possibility of overflow, reception of image data for the given page from said computer is stopped, said rendering unit completes rendering of the display list thus far stored in the intermediate memory for provision to said band buffer, with said band buffer providing the rendered bands to said compressor for compression and storage in said compressed image memory, with the thus far stored display list then being deleted from said intermediate memory, with reception of image data for the given page from said computer subsequently being resumed, with a subsequent display list for the given page being stored in said intermediate memory for subsequent rendering by said rendering unit, storage in said band buffer, compression by said compressor, and storage in said compressed image memory, wherein when the complete given page is stored, said expander expands the complete given page for provision to the second input of said image processor;
• and
• an image forming device connected to the output of said image processor for forming an image of the given page line by line in accordance with an output from said image processor.